/library/oar/handle/123456789/10109 2026-05-29T19:51:02Z 2026-05-29T19:51:02Z /library/oar/handle/123456789/10277 2017-07-20T08:20:03Z 2014-01-01T00:00:00Z

Title: Assessing the design options for the optimization of a 2MWp ground mounted PV system in Malta Abstract: The objective of large scale PV installation in space constrained countries has gradually shifted from production maximisation to that of reaching an optimised economic performance. A main reason for this has been the decline in the price of PV modules. This has resulted in systems with lower tilt angles, increased mutual shading and overloading of inverters by design in the continuous quest of balancing reduced yields with development costs over the entire lifespan of the project. This approach has shifted the traditional view of evaluating a PV installation from a Euro/watt approach to the use of current optimisation metrics of Levelised Cost Of Electricity (LCOE) or Internal Rate of Return (IRR). This is the concept of value based design. In fact, optimisation can be simply described as a balancing act, evaluating tradeoffs to assess which combination gives the best economic performance. By its very nature, optimisation is an iterative process. Large installations provide room for design flexibility where the additional returns justify the energy and cost of the optimisation work. Optimisation work is very much site specific. What has been proven as the best approach for other countries does not necessary apply to Malta. This dissertation evaluates a number of design parameters which, together with production modelling within the context of the Maltese solar climate, aims at identifying an optimum design for the building of a 2MWp ground mounted PV farm. Among the aspects considered, are layout optimisation with issues of tilt and cross shading and inverter architecture whether string or central, including the controversial dc-toac ratio. Central inverter architecture is found to provide a better economic performance over string inverter architecture. The dominant factor in this respect is that no allowance has to be made for the complete replacement of a central inverter within the project life as is the case with string inverters. Yield optimisation is reached with a dc-to-ac ratio of 1.20, however, economic optimisation with respect to string inverter architecture is achieved with a much higher ratio of 1.38. The economic metrics have shown a high sensitivity to the method of vi land acquisition for the project. In the case of an outright purchase, best economic performance is reached with those plant parameters which minimise land usage, that is, low tilt angle and high limit angle. In the case of a land lease agreement, maximising energy production takes the leading role over land usage minimisation resulting in a plant utilising a higher tilt angle and a lower limit angle when compared to the previous scenario. This research highlights the importance that plant optimisation studies should be undertaken prior to any large scale PV development, as plant parameters which guarantee the best return on investment are not static but vary according to the costs and revenue structures of the project at the time of development. Description: M.SC.SUS.ENERGY

2014-01-01T00:00:00Z /library/oar/handle/123456789/10208 2017-08-04T08:06:33Z 2014-01-01T00:00:00Z

Title: Energy recovery from waste : is thermal treatment a viable option for Malta? Abstract: In 2012 Malta generated 246,110 tonnes of Municipal Solid Waste (MSW) and a further 158,167 tonnes of other waste. Landfilling amounted to 268,140 tonnes while the total energy generated from waste in 2012 was 4.09 GWh equivalent to 0.47 MW. The Waste Management Plan for the Maltese Islands 2014–2020 (MSDEC, 2014) issued earlier this year, indicates that Malta is still at cross-roads on how to treat the waste ending up in the landfill – whether by some means of local energy recovery, exporting the waste or further landfilling. This dissertation intends to analyse a potential waste management roadmap for Malta for the period 2015–2040 taking into account the present and committed waste management infrastructure together with the hypothetical introduction of a Thermal Treatment Facility (TTF) in 2021, initially to complement the waste treatment portfolio, until it eventually becomes the mainstay for the treatment of mixed waste in Malta. This dissertation is divided into two main parts. The first part constitutes a literature review on the documentation related to waste management in Malta in an effort concentrated at understanding the current state of play in this sector and to try to figure out the reasons and motives behind the apparent course of action taken to manage waste. In the second part, a model is used to depict the Maltese waste mass flows in five reference years as it transforms from collection to processing until it eventually becomes some form of output. These reference years are chosen to represent 2012 as the year with the latest official waste data available; 2016 being the first full year when Malta North is expected to come online; 2021 as the year when hypothetically a Thermal Treatment Facility is introduced in the waste management scene and 2025 and 2030 as the years when the MBTs at SAWTP4 and Malta North are expected to be decommissioned. This enables to map out and compare the resultant changes in the waste outputs, the effect on the biowaste and recycling targets and the resultant waste management cost as it varies consequential to the different waste treatment methods adopted arising from the different treatment plants employed. The data that emerges from the model employed shows that, in spite of the operation of the Mechanical and Biological Treatment plants (MBTs), 70% of the total waste generated still ends up being landfilled equivalent to 86% of the waste that is not recycled. In contrast, if a Thermal Treatment Facility is introduced, landfilling goes down to 20% of the total waste generated or 30% of the mixed stream waste. Once the TTF is operational, there is no significant effect on landfill quantities if the MBT’s are no longer in service. Furthermore, the TTF during its operational lifetime brings along the beneficial opportunity to mine around 3.7 million tonnes of municipal waste deposited in the engineered landfill – thereby creating valuable void space and extending considerably its lifetime. Thermal treatment5 could also be a solution for Malta to achieve its landfill targets in terms of biowaste and recyclables – both earmarked by the EU for a complete landfill ban as of 2025. Description: M.SC.SUS.ENERGY

2014-01-01T00:00:00Z /library/oar/handle/123456789/10206 2017-08-09T10:52:29Z 2014-01-01T00:00:00Z

Title: Evaluation of voltage optimization as an effective measure to improve energy efficiency Abstract: Voltage Optimization, also referred to as Conservation Voltage Reduction, has long been identified as a potential measure to reduce electrical energy consumption. This scope of this study was to evaluate the current scientific understanding of the use and effects of voltage on energy consumption. The strategies to applying Conservation Voltage Reduction (CVR) were also researched, as well as the various approaches to modelling the effect of voltage on energy consumption. A Measurement & Verification (M&V) protocol was developed in order to study the effects of voltage reduction on two systems of different size and differing application, i.e. domestic and small industrial. The data collected was analysed to determine the potential of applying this as an energy conservation measure in Malta. From literature reviewed voltage was found to be an important characteristic of power quality which influences the operation of electrical equipment. Voltage has been harmonized in the European Union to 230V 10% leading to situations where equipment operates at a voltage different than design voltage. Research dating back many decades outlines the effect of voltage on energy consumption, and in the vast majority there is agreement that lower voltage levels result in reduced consumption. Description: M.SC.SUS.ENERGY

2014-01-01T00:00:00Z /library/oar/handle/123456789/10127 2017-05-30T08:39:51Z 2014-01-01T00:00:00Z

Title: Analysis of potential wave energy converters around the Maltese archipelago Abstract: The main scope of this research is to provide a technical basis on the wave energy potential around the Maltese islands. The results from the literature review, given that limited reports and studies have been commissioned, show that there is sufficient data to base an analysis of the wave resource prospective. From this data, potential candidate sites were assessed and discussed versus the current available technology. The energy yields that these designated areas offer were calculated given current conversion efficiencies and capacity factors of commercial available wave energy converters. This helped to reach the objectives of the study and figures of potential generated electrical energy in MWh per year are calculated. The results provide room for discussion and can be challenged in the near future given the fast pace of technological improvement in the wave energy industry. Description: M.SC. SUS. ENERGY

2014-01-01T00:00:00Z